The power needed to operate electrical applicances such as television sets, refrigerators and other such devices as drills and impact hammers is obtained from branch outlets commonly available in existing buildings. The power usually enters the building from a two or three wire alternating current power line which divides into numerous branch lines terminating in electric fixtures and branch outlets. Typically such branch outlets deliver power in the form of alternating current at a voltage, usually between 110 and 120 volts, and are limited by fusing or otherwise to a prescribed maximum current, usually 15 amperes, which therefore limits the power to be drawn therefrom, to avoid overheating of branch lines and particularly of branch outlets.
To operate some devices, however, such as larger electric demolition hammers or air conditioners, substantially more power is needed, and to provide such power either greater voltage or greater amperage or both is required. While many existing buildings have one or more branch outlets powered at nominal 230 volts or have outlets limited to higher amperage, such higher-power branch outlets are usually either inconveniently located, or are relatively inaccessible. Accordingly, to use such higher powered devices, it is necessary either to install a higher power branch outlet, usually requiring considerable building change and expense, or to supply a portable gasoline-engine-driven electrical generator, which is expensive and creates much noise and smog.
Accordingly, there is an important need for a less expensive more convenient means for supplying higher power for such appliances, for example, from existing electrical building circuits. The present invention fulfills that need.